Walter



.P. TRUMP.

Steam-Boiler.

' INVENTOR M,

i? I ATTORNEY alllll Patented Mav 25 lLPEliia. FHOTWLITHOGRAPMER.WASHINGTON D, C.

. Ill-w WITNESSES ting snugly on UNITED A STATES PATENT GFFICE.

FULLER TRUMP, OF SPRINGFIELD, 01110, ASSIGNOR TO JOHN w. EooK- WALTER,OF SAME PLACE.

STEAM-BOILER.

SPECIFICATION forming part of Letters Patent No. 228,143, dated May 25,1880.

Application filed April '1, 1880. (ModeL) To all whom it may concern:

Be it known that I, FULLER TRUMP, of Springfield, in the county ofClarke and State of Ohio, have invented a new and valuable Improvementin Steam-Boilers 5 and I do hereby declare that the following is a full,clear, and exact description of the construction and operation of thesame, reference being bad to the annexed drawings, making a part of thisspecification, and to the letters and figures of reference markedthereon.

Figure 1 of the drawings is a representation of a vertical centralsection of my improved boiler, and Fig. 2 is a bottom view thereof.

This invention has relation to'improvements in steam boilers of thatdescription having castmetal interiors.

The object of the invention is mainly to prevent the cracking of thecrown-sheet during the operation of casting it, or during the heatingand cooling of the same, owing to the unequal expansion and contractionthereof; and it consists in the construction and novel arrangement ofparts, as hereinafter shown and described.

In the annexed drawings, the letter A designates an upright or verticalboiler, in connection with which I propose to illustrate my invention. Bis a cylindrical wrought metal shell, and O a cast-metal cylinder ofsomewhat less diameter exteriorly than the shell, and constituting thefire-chamber or furnace. This chamber is provided at its lower end witha vertical flange, a, secured to the lower edge of the shell by means ofbolts a, and at its upper edge with a horizontal flange, b, by means ofwhich it is secured to the flue-section D next above. This section hasalso a flange, d, fitflange b of the furnace-section O, and securedthereto by the through-bolts c.

The section D is composed of two horizontal disks, (1 cl, having acentral flue, d, and a number of side flues, d, the whole being cast inone piece, and the flues being sufficiently far apart to formwater-spaces between them. There may be one or more of these sections,according to the height of the boiler.

Above the section D is another section, D, constructed with a disk, e,at its lower part, of the same diameter as the disk d and fitting snuglythereon, and with flues e e in corresponding positions with the fines d"d, and forming the upward continuation thereof. The flues e e terminateabove in a transversely concavo'convex plate, f, the convexity of whichis upward.

The section D is secured by means of bolts 9 to a cast annulus, G,fitting snugly within the shell, and having a flange, Z,for thereception of the bolts.

It is preferred to make the flue part of the thereof may be made withless risk.

The rounded or arched form of the crownsheet f of the boiler is superiorto the flat form in this, that in casting the latter the shrinkage ofthe metal near its perimeter is so much greater and in advance of theparts nearer the center that the strain is unequal and sometimes causesthe sheet to open or fracture near its periphery; but the rounded formof the sheet obviates the unyielding rigidity of the flat sheet, andpermits it to cool off after casting without danger of breaking orcracking.

What I claim as new, and desire to scour by Letters Patent, is-

l. The combination, with a steam-boiler, of a flue-castin g providedwith upper and lower flue-sheets, the upper one of which is arched, saidcasting being provided withflanges and flues, the whole cast in onepiece, as specified.

2. The combination, with the arched castmetal flue sheet f, its flues ee", and the wrought-iron shell B, of the connecting-annulus G,substantially as specified.

In testimony that I claim the above I have hereunto subscribed my namein the presence of two witnesses.

FULLER TRUMP.

Witnesses F. G. Gown, 0. B. J oHNsoN.

boiler in sections, in order that the casting.

